This invention relates generally to a fastener and a driver therefor and more particularly to a fastener such as a screw or bolt having a recessed head to receive the driver therein. The head of a conventional slotted fastener is easily damaged by the conventional driver. Also, in fasteners of the Phillips type having recessed heads, the internal flutes are easily damaged when the driver is ill-fitting or turned with excessive force. Further, the driver tends to rise out of the recess or "cam out" when high force is required to turn the fastener and when the driver is not coaxially aligned with the recess of the screw. Neither type of fastener is conveniently driven when the axis of the driver is not collinear with the axis of the fastener. This makes it difficult to drive the fasteners in relatively inaccessible locations where direct in-line driving is not possible. Offset drivers, ratchets and flexible drive shafts are frequently resorted to to alleviate the difficulties presented by misalignment in the axes of the fastener and driver.
What is needed is a fastener and a compatible driver which are simple in nature and allow for efficient driving of the fastener from a misaligned position. It is also desirable that engagement between the fastener and driver is easily maintained during driving and the fastener is not damaged. Premature wearing out of the driver due to slippage and "camming out" is quite costly in production due to downtime as well as replacement of drivers.
It has been found in the manufacture of screws which incorporate head recesses made up of intersecting planes, such as in the Phillips type or slotted or hexagonal recesses, that there is great difficulty encountered in plating into the recesses.
It is therefore desirable to have a recess with smooth-flowing walls into which electroplating can penetrate.